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Radiation uniformity is important for Z-pinch dynamic hohlraum driven fusion. In order to understand the radiation uniformity of Z-pinch dynamic hohlraum, the code MULTI-2D with a new developed magnetic field package is employed to investigate the related physical processes on Julong-I facility with drive current about 7–8 MA. Numerical simulations suggest that Z-pinch dynamic hohlraum with radiation temperature more than 100 eV can be created on Julong-I facility. Although some X-rays can escape out of the hohlraum from Z-pinch plasma and electrodes, the radiation field near the foam center is quite uniform after a transition time. For the load parameters used in this paper, the transition time for the thermal wave transports from r = 1 mm to r = 0 mm is about 2.0 ns. Implosion of a testing pellet driven by cylindrical dynamic hohlraum shows that symmetrical implosion is hard to achieve due to the relatively slow propagation speed of thermal wave and the compression of cylindrical shock in the foam. With the help of quasi-spherical implosion, the hohlraum radiation uniformity and corresponding pellet implosion symmetry can be significantly improved thanks to the shape modulation of thermal wave front and shock wave front. Keywords: Z-pinch, Dynamic hohlraum, Radiation uniformity, Shock wave, Thermal wave, PACS codes: 52.58.Lq, 52.59.Qy, 52.65.Kj

The effects of high-Z dopant on the laser-driven ablative Richtmyer–Meshkov instability (RMI) are investigated by theoretical analysis and radiation hydrodynamics simulations. It is found that the oscillation amplitude of ablative RMI depends on the ablation velocity, the blow-off plasma velocity and the post-shock sound speed. Owing to enhancing the radiation at the plasma corona and increasing the radiation temperature at the ablation front, the high-Z dopant in plastic target can significantly increase the ablation velocity and the blow-off plasma velocity, leading to an increase in oscillation frequency and a reduction in oscillation amplitude of the ablative RMI. The high-Z dopant in plastic target is beneficial to reduce the seed of ablative Rayleigh–Taylor instability. These results are helpful for the design of direct drive inertial confinement fusion capsules.

Compact acceleration of a tightly collimated relativistic electron beam with high charge from a laser-plasma interaction has many unique applications. However, currently the well-known schemes, including laser wakefield acceleration from gases and vacuum laser acceleration from solids, often produce electron beams either with low charge or with large divergence angles. In this work, we report the generation of highly collimated electron beams with a divergence angle of a few degrees, quasi-monoenergetic spectra peaked at the MeV level, and extremely high charge ($\sim$100 nC) via a powerful sub-ps laser pulse interacting with a solid target in grazing incidence. Particle-in-cell simulations illustrate a new direct laser acceleration scenario, in which the self-filamentation is triggered in a large-scale near-critical-density plasma and electron bunches are accelerated periodically and collimated by the ultra-intense electromagnetic field. The energy density of such electron beams in high-Z materials reaches to $\sim10^{12} \mathrm{J/m^{3}}$, making it a promising tool to drive warm or even hot dense matter states., 7 pages, 6 figures

Effect of the bromine-dopant in plastic target on laser-driven ablative Richtmyer-Meshkov instability is investigated by radiation hydrodynamics simulations. It is found that the bromine-dopant can significantly reduce the perturbation growth and increase the oscillation frequency of ablative Richtmyer-Meshkov instability. The Br-dopant in plastic target increases the radiation temperature at ablation front, which leads to a large ablation velocity. According to the theoretical analysis, the decay of perturbation growth and the increase of the oscillation frequency of ablative Richtmyer-Meshkov instability are attributed to the large ablation velocity.

It is shown by particle-in-cell simulation that intense circularly polarized (CP) laser light can be contained in the cavity of a solid-density circular Al-plasma shell for hundreds of light-wave periods before it is dissipated by laser-plasma interaction. A right-hand CP laser pulse can propagate with almost no reflection and attenuation into the cavity through a highly magnetized overdense H-plasma slab filling the entrance hole. The entrapped laser light is then multiply reflected at the inner surfaces of the slab and shell plasmas, slowly losing energy to the latter. Compared to that of the incident laser, the frequency is only slightly broadened and the wave vector slightly modified by the appearance of weak nearly isotropic and homogeneous fluctuations.

Ionization-induced electron injection in a chirped laser pulse driven wakefield acceleration is investigated through particle-in-cell simulations. We find that negative (positive) chirp can longitudinally stretch (compress) laser pulse, and the wakefield amplitude can be enhanced regardless of the chirp sign. On the other hand, the rapid compression of a positively chirped pulse leads to the decrease of the wakefield potential difference, which breaks the ionization injection condition and consequent injection truncation occurs. The effective injection only lasts for a few hundred micrometers and the detailed injection length is determined by the chirp parameter. As a result, a highly tunable quasi-monoenergetic electron beam with narrow energy spread, hundreds of MeV central energy and tens of pC charge can be stably produced by this scheme.

Energetic divergent proton beams can be generated in the interaction of ultra-intense laser pulses with solid-density foil targets via target normal sheath acceleration (TNSA). In this paper, a scheme using a capillary to reduce the proton beam divergence is proposed. By two-dimensional particle-in-cell (PIC) simulations, it is shown that strong transverse electric and magnetic fields rapidly grow at the inner surface of the capillary when the laser-driven hot electrons propagate through the target and into the capillary. The spontaneous magnetic field collimates the electron flow, and the ions dragged from the capillary wall by hot electrons neutralize the negative charge and thus restrain the transverse extension of the sheath field set up by electrons. The proton beam divergence, which is mainly determined by the accelerating sheath field, is therefore reduced by the transverse limitation of the sheath field in the capillary.

Mechanisms of fast electron energy deposition in dense magnetized plasma are studied by hybrid particle-in-cell/fluid simulations. It is found that the energy deposition ratio of Ohmic heating and collisional heating can be enhanced significantly as an Al target is presented in a strongly axial magnetic field, attributed to the fast electrons rotating around the axial field. The weight of Ohmic heating is increased with laser intensity during ultraintense laser-driven fast electrons propagating both in magnetized and unmagnetized solid targets, which is the dominant heating mechanism as the laser intensity is greater than 1018 W/cm2 compared to the collisional heating. The degree of the axial magnetic field effect on the fast electron energy deposition mechanisms is dependent on target materials, which is much weaker for low-Z targets, such as CH2. The results here should be helpful for the target designing of fast electron applications.Mechanisms of fast electron energy deposition in dense magnetized plasma are studied by hybrid particle-in-cell/fluid simulations. It is found that the energy deposition ratio of Ohmic heating and collisional heating can be enhanced significantly as an Al target is presented in a strongly axial magnetic field, attributed to the fast electrons rotating around the axial field. The weight of Ohmic heating is increased with laser intensity during ultraintense laser-driven fast electrons propagating both in magnetized and unmagnetized solid targets, which is the dominant heating mechanism as the laser intensity is greater than 1018 W/cm2 compared to the collisional heating. The degree of the axial magnetic field effect on the fast electron energy deposition mechanisms is dependent on target materials, which is much weaker for low-Z targets, such as CH2. The results here should be helpful for the target designing of fast electron applications.

The generation of high-energy-density (HED) plasma jet from a laser ablating thin cone target is studied theoretically and by numerical simulations. Theoretical analysis and 1D simulations show that a maximum kinetic energy conversion efficiency (CE) of 26% can be achieved when nearly 80% of the foil is ablated by laser. A HED plasma jet is generated when an intense laser (∼1015 W/cm2) irradiates the cone target, inducing a great enhancement of energy density compared to that of the planar target, which is attributed to the cumulative effect of the cone shape and the new generation mechanism of jet, i.e., laser directly accelerating the cone wall onto the axis. The characteristic of jet is influenced by the cone geometry, i.e., thickness and cone angle. It is found that a cone with a half opening angle around 70° and the optimized thickness (∼5 μm) can induce a jet with a high CE and long duration, whose peak energy density can reach 3.5 × 1015 erg/cm3. The results can be beneficial for laser-driven novel neutron sources and other fusion related experiments, where HED plasma jet can be applied.

Synthesis and Characterization of Novel Trifunctional Fluorine Containing Epoxy Resins Based on 1,1,1-Tris(2,3-epoxypropoxyphenyl)-2,2,2-trifluoroethane

Two series of fluorinated aromatic polyamides derived from two novel monomers, 5-(4-trifluoromethylphenoxy)isophthaloyl dichloride (3FPC) and 5-(3,5-bistrifluoromethyl-phenoxy)isophthaloyl dichloride (6FPC) with various aromatic diamines were synthesized and characterized. Experimental results indicated that the fluorinated aromatic polyamides showed good solubility in many organic solvents. The solubility of the polyamides was affected by the trifluoromethyl substituents and the pendent phenoxy groups in the polymer backbone. The fluorinated polyamides have good thermal stability with the glass transition temperature of 206–285 °C, the temperature at 5% weight loss of 442–460 °C in nitrogen. The polyamide films also exhibited good mechanical properties and excellent electrical and dielectric properties. The fluorinated groups in the polymer backbone have played an important role in the improvement of electrical and dielectric performance of polymer.

A novel fluorinated aromatic dianhydride, 4,4′-[2,2,2-trifluoro-1-(3-trifluoromethyl-phenyl)ethylidene]diphthalic anhydride (TFDA) was synthesized by coupling of 3′-trifluoromethyl-2,2,2-trifluoroacetophenone with o-xylene under the catalysis of trifluoromethanesulfonic acid, followed by oxidation of KMnO4 and dehydration. A series of fluorinated aromatic polyimides derived from the novel fluorinated aromatic dianhydride TFDA with various aromatic diamines, such as p-phenylenediamine (p-PDA), 4,4′-oxydianiline (ODA), 1,4-bis(4-aminophenoxy)benzene (p-APB), 1,3-bis(4-amino-phenoxy)benzene (m-APB), 4-(4-aminophenoxy)-3-trifluoromethylphenylamine (3FODA) and 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene (6FAPB), were prepared by polycondensation procedure. All the fluorinated polyimides were soluble in many polar organic solvents such as NMP, DMAc, DMF, and m-cresol, as well as some of low boiling point organic solvents such as CHCl3, THF, and acetone. Homogeneous and stable polyimide solutions with solid content as high as 35–40 wt % could be achieved, which were prepared by strong and flexible polyimide films or coatings. The polymer films have good thermal stability with the glass transition temperature of 232–322 °C, the temperature at 5% weight loss of 500–530 °C in nitrogen, and have outstanding mechanical properties with the tensile strengths of 80.5–133.2 MPa as well as elongations at breakage of 7.1–12.6%. It was also found that the polyimide films derived from TFDA and fluorinated aromatic diamines possess low dielectric constants of 2.75–3.02, a low dissipation factor in the range of 1.27–4.50 × 10−3, and low moisture absorptions

A series of fluorinated poly(amide imide)s were prepared from 1,4-bis(2′-trifluoromethyl-4′-trimellitimidophenoxy)benzene and various aromatic diamines [3,3′,5,5′-tetramethyl-4,4′-diaminediphenylmethane, α,α-bis(4-amino-3,5-dimethyl phenyl)-3′-trifluoromethylphenylmethane, 1,4-bis(4′-amino-2′-trifluoromethylphenoxy)benzene, 4-(3′-trifluoromethylphenyl)-2,6-bis(3′-aminophenyl)pyridine, and 1,1-bis(4′-aminophenyl)-1-(3′-trifluoromethylphenyl)-2,2,2-trifluoroethane]. The fluorinated poly(amide imide)s, prepared by a one-step polycondensation procedure, had good solubility both in strong aprotic solvents, such as N-methyl-2-pyrrolidinone, dimethylacetamide, dimethylformamide, dimethyl sulfoxide, and cyclopentanone, and in common organic solvents, such as tetrahydrofuran and m-cresol. Strong and flexible polymer films with tensile strengths of 84–99 MPa and ultimate elongation values of 6–9% were prepared by the casting of polymer solutions onto glass substrates, followed by thermal baking. The poly(amide imide) films exhibited high thermal stability, with glass-transition temperatures of 257–266 °C and initial thermal decomposition temperatures of greater than 540 °C. The polymer films also had good dielectric properties, with dielectric constants of 3.26–3.52 and dissipation factors of 3.0–7.7 × 10−3, and acceptable electrical insulating properties. The balance of excellent solubility and thermal stability associated with good mechanical and electrical properties made the poly(amide imide)s potential candidates for practical applications in the microelectronics industry and other related fields. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1831–1840, 2003

A novel fluorinated tetramethyl-substituted diphenylmethanediamine, α,α-bis(4-amino-3,5-dimethylphenyl)-3′-trifluoromethylphenylmethane (TFPM) was synthesized via a straightforward two-step procedure with high yield, which was then employed to react with 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) to afford soluble and inherent photoimageable polyimide BTDA–TFPM [PI(BTDA–TFPM)]. Experimental results indicated that PI(BTDA–TFPM) possesses good combined chemical and physical properties, of which thermal stability with initial thermal decomposition temperature of 526 °C and glass transition temperature of 298 °C. The polyimide has excellent solubility both in strong bipolar solvents, such as NMP and DMAc, and in common organic solvents, such as THF and dioxane, etc. Strong and flexible polymer coatings or films could be prepared by just casting the polymer solution on glass substrate, followed by thermal baking at a temperature lower than 200 °C. The novel polyimide has good electric insulating properties and low dielectric constant and dissipation factor. Fine photopattern could be processed by directly exposing the polyimide coating upon UV i-line, followed by developing with an organic solution developer.

Effects of bromine (Br) dopant on the growth of radiation-driven ablative Rayleigh–Taylor instability (RTI) in plastic foils are studied by radiation hydrodynamics simulations and theoretical analysis. It is found that the Br-dopant in plastic foil reduces the seed of ablative RTI. The main reasons of the reduction are attributed to the smaller oscillation amplitude of ablative Richtmyer–Meshkov instability (RMI) induced by the smaller post-shock sound speed, and the smaller oscillation frequency of ablative RMI induced by the smaller ablation velocity and blow-off plasma velocity. The Br-dopant also decreases the linear growth rate of ablative RTI due to the smaller acceleration. Treating the perturbation growth as a function of foil's displacement, the perturbation growth would increase in Br-doped foil at the phase of ablative RTI, which is attributed to the decrease of the ablation velocity and the density gradient scale length. The results are helpful for further understanding the influence of high-Z dopant on the radiation-driven ablative RTI.

A mechanism of the acceleration and focusing of quasi-monoenergetic proton beams from a thin arched carbon-hydrogen target irradiated by a relativistic-intensity laser pulse is investigated by multi-dimensional particle-in-cell (PIC) simulations. As an intense linearly polarized laser pulse impinges on the thin target, a considerable number of electrons are evacuated, leading to Coulomb explosion in the excess positive charges left behind. Accompanying with the acceleration, the protons are focused ballistically in the Coulomb field, which is mainly contributed by the carbon ions. It is demonstrated that a quasi-monoenergetic proton bunch with the energy-density as high as 1017 J/m3 is produced by using a laser pulse with the intensity of 1021 W/cm2. An analytical model is proposed to predict the proton energy and the focal position, which is fairly consistent with PIC simulations.

A scheme in which carbon ion bunches are accelerated to a high energy and density by a laser pulse (∼1021 W/cm2) irradiating cone targets is proposed and investigated using particle-in-cell simulations. The laser pulse is focused by the cone and drives forward an ultrathin foil located at the cone's tip. In the course of the work, best results were obtained employing target configurations combining a low-Z cone with a multispecies foil transversely shaped to match the laser intensity profile.

An analytical model for energy absorption during the interaction of an ultrashort, ultraintense laser with an overdense plasma is proposed. Both the compression effect of the electron density profile and the oscillation of the electron plasma surface are self-consistently included, which exhibit significant influences on the laser energy absorption. Based on our model, the general scaling law of the compression effect depending on laser strength and initial density is derived, and the temporal variation of the laser absorption due to the boundary oscillating effect is presented. It is found that due to the oscillation of the electron plasma surface, the laser absorption rate will vibrate periodically at $\ensuremath{\omega}$ or 2$\ensuremath{\omega}$ frequency for the $p$-polarized and $s$-polarized laser, respectively. The effect of plasma collision on the laser absorption has also been investigated, which shows a considerable rise in absorption with increasing electron-ion collision frequency for both polarizations.

Simultaneous generation of monoenergetic tunable protons and carbon ions from intense laser multi-component nanofoil interaction is demonstrated by using particle-in-cell simulations. It is shown that, the protons with the largest charge-to-mass ratio are instantly separated from other ion species and are efficiently accelerated in the ”phase stable” way. The carbon ions always ride on the heavier oxygen ion front with an electron-filling gap between the protons and carbon ions. At the cost of widely spread oxygen ions, monoenergetic collimated protons and carbon ions are obtained simultaneously. By modulating the heavier ion densities in the foil, it is capable to control the final beam quality, which is well interpreted by a simple analytical model.

Generation of relativistic electron (RE) beams during ultraintense laser pulse interaction with plasma targets is studied by collisional particle-in-cell simulations. A strong magnetic field with a transverse scale length of several local plasma skin depths, associated with RE current propagation in the target, is generated by filamentation instability in collisional plasmas, inducing a great enhancement of the divergence of REs compared to that of collisionless cases. Such an effect is increased with laser intensity and target charge state, suggesting that the RE divergence might be improved by using low-Z materials under appropriate laser intensities in future fast ignition experiments and in other applications of laser-driven electron beams.

We propose a new scheme to obtain a compact ultra-bright, high-energy-density γ ray source by ultra-intense laser interaction with a near-critical-density (NCD) plasmas filled gold cone-capillary. By using the particle-in-cell code EPOCH, it is shown that NCD electrons are accelerated by the laser ponderomotive force in the gold cone and emit strong radiation. Considering the effect of large radiation back-reaction force, some electrons are kicked into the laser field. The trapped electrons oscillate significantly in the transverse direction and emit ultra-bright γ ray in the forward direction. By attaching a capillary to the gold cone, the trapped electrons are able to keep oscillating for a long distance and the radiation emission can be significantly enhanced. Three-dimensional simulations show that the total γ photon flux with the photon energy in the range of 3 MeV to 30 MeV is approximately 1013/shot, and the corresponding peak brightness is in the order of 1023 photons/s/mm2/mrad2/0.1%BW. The avera...

A novel double-foil configuration is proposed to improve the laser to x-ray conversion efficiency from laser irradiating a solid target. One-dimensional radiation hydrodynamic simulations show that the total x-ray conversion efficiency for the double-foil target is as high as 54.7%, which has a 10% improvement compared with the normal target. The improvement is mainly due to the enhanced soft x-ray emissions. Influences of the target geometry parameters on the x-ray conversion efficiency are investigated. Detailed energy distributions and the individual contributions of the two foils to the thermal and kinetic energy terms are presented. It is found that the main energy terms are mostly determined by the first foil, and the enhancement of radiation is attributed to the lower ion kinetic energy of the double-foil target.

Propagation of intense circularly polarized laser pulses in strongly magnetized inhomogeneous plasmas is investigated. It is shown that a left-hand circularly polarized laser pulse propagating up the density gradient of the plasma along the magnetic field is reflected at the left-cutoff density. However, a right-hand circularly polarized laser can penetrate up the density gradient deep into the plasma without cutoff or resonance and turbulently heat the electrons trapped in its wake. Results from particle-in-cell simulations are in good agreement with that from the theory. (c) 2015 AIP Publishing LLC.

The radiation trapping effect (RTE) of electrons in the interaction of an ultra-intense laser and a near-critical-density plasma-filled gold cone is numerically investigated by using the particle-in-cell code EPOCH. It is found that, by using the cone, the threshold laser intensity for electron trapping can be significantly decreased. The trapped electrons located behind the laser front and confined near the laser axis oscillate significantly in the transverse direction and emit high-energy photons in the forward direction. With parameters optimized, a narrow photon angular distribution and a high-energy conversion efficiency from the laser to the photons can be obtained. The proposed scheme may offer possibilities to demonstrate the RTE of electrons in experiments at approachable laser intensities and serve as a novel table-top ray source.

A foil-in-cone target is proposed to enhance stable laser-radiation-pressure-driven proton acceleration by avoiding the beam degradation in whole stage of acceleration. Two and three-dimensional particle-in-cell simulations demonstrate that the guiding cone can substantially improve the spectral and spatial properties of the ion beam and lead to better preservation of the beam quality. This can be attributed to the focusing effect of the radial sheath electric fields formed on the inner walls of the cone, which co-move with the accelerated foil and effectively suppress the undesirable transverse explosion of the foil. It is shown that, by using a transversely Gaussian laser pulse with intensity of ∼2.74 × 1022 W∕cm2, a quasi-monoenergetic proton beam with a peak energy of ∼1.5 GeV/u, density ∼10nc, and transverse size ∼1λ0 can be obtained.

By using two-dimensional particle-in-cell simulations, we propose a scheme for strong coupling of a petawatt laser with an opening gold cone filled with near-critical-density plasmas. When relevant parameters are properly chosen, most laser energy can be fully deposited inside the cone with only 10% leaving the tip opening. Due to the asymmetric ponderomotive acceleration by the strongly decayed laser pulse, high-energy-density electrons with net laser energy gain are accumulated inside the cone, which then stream out of the tip opening continuously, like a jet. The jet electrons are fully relativistic, with speeds around 0.98−0.998 c and densities at 1020/cm3 level. The jet can keep for a long time over 200 fs, which may have diverse applications in practice.

Transport of fast electrons driven by an ultraintense laser through a tracer layer buried in solid targets is studied by particle-in-cell simulations. It is found that intense resistive magnetic fields, having a magnitude of several thousand Tesla, are generated at the interfaces of the materials due to the steep resistivity gradient between the target and tracer layer. Such magnetic fields can significantly inhibit the fast electron propagation. The electrons that can penetrate the first interface are mostly confined in the buried layer by the magnetic fields and cause heating of the tracer layer. The lateral extent of the heated region can be significantly larger than that of the relativistic electron beam. This finding suggests that the relativistic electron divergence inferred from Kα x-ray emission in experiments might be overestimated.

A series of fluorinated polyimide films have been prepared by casting the poly (amic acid) solution, which were synthesized by polycondensation of 4,4-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) with various fluorinated aromatic diamines, including 1,4-bis (4-amino-2-trifluoromethylphenoxy) benzene (p6FPB), 4-[3', 5'-bis-(trifluoromethyl) phenyl]-2,6-bis (4"-amino-phenyl) pyridine (pTFPP) and 4-[3',5'-bis-(trifluoromethyl phenyl)-2,6-bis (3"-aminophenyl) pyridine] (mTFPP), followed by thermal imidization at elevated temperatures. The strong and flexible polyimide films, PI-1 (6FDA-p6FPB), PI-2 (6FDA-pTFPP) and PI-3 (6FDA-mTFPP) exhibited good thermal stability and high mechanical properties. The films also showed high surface and volume resistances and low dielectric constant. The excellent combined properties of the materials make them great candidates for microelectronic packaging.

The enhanced target normal sheath acceleration of ions in laser target interaction via the laser relativistic self-focusing effect is investigated by theoretical analysis and particle-in-cell simulations. The temperature of the hot electrons in the underdense plasma is greatly increased due to the occurrence of resonant absorption, while the electron-betatron-oscillation frequency is close to its witnessed laser frequency [Pukhov et al., Phys. Plasma 6, 2847 (1999)]. While these hot electrons penetrate through the backside solid target, a stronger sheath electric field at the rear surface of the target is induced, which can accelerate the protons to a higher energy. It is also shown that the optimum length of the underdense plasma is approximately equal to the self-focusing distance.

To clarify the immuno-active LH (i-LH) and bioactive LH (b-LH) responses and qualitative changes in the circulating LH to testosterone undecanoate (TU) injection.Eight men with Klinefelter's syndrome were recruited for the study. They received crossover injections of TU at doses of 500 and 1000 mg. Serum i-LH and b-LH levels before and at various time intervals after TU injection were measured and the serum i-LH, b-LH, b-LH/i-LH (B/I) and testosterone/sex hormone-binding globulin (T/SHBG) ratio in LH-responders and LH non-responders were compared.A parallel suppression of serum i-LH and b-LH was consistent with their overall high correlation between each other (r = 0.84, P0.001). Mean serum i-FSH levels were decreased by TU injection at both doses without dose-response effects. LH-responders had lower baseline serum i-LH and b-LH, and higher E2 levels and T/SHBG ratio. There was a quantitative change in serum LH as induced by TU without qualitative change within LH-responders os LH-non-responders.A high loading dose (1000 mg) of TU is important for the initial suppression of LH. With the lower dose (500 mg), repeated injections will be required to attain such LH suppression for the purpose of fertility regulation. The lower baseline serum i-LH level may be an intrinsic characteristic of LH-responders.

An analytical model for laser-plasma interaction during the oblique incidence by an ultrashort ultraintense p-polarized laser on a solid-density plasma is proposed. Both the resonant absorption and not-so-resonant absorption are self-consistently included. Different from the previous theoretical works, the physics of resonant absorption is found to be valid in more general conditions as the steepening of the electron density profile is considered. Even for a relativistic intensity laser, resonant absorption can still exist under certain plasma scale length. For shorter plasma scale length or higher laser intensity, the not-so-resonant absorption tends to be dominant, since the electron density is steepened to a critical level by the ponderomotive force. The laser energy absorption rates for both mechanisms are discussed in detail, and the difference and transition between these two mechanisms are presented.

Laser shaping of a relativistic circularly polarized laser pulse in ultra-intense laser thin-foil interaction is investigated by theoretical analysis and particle-in-cell simulations. It is found that the plasma foil as a nonlinear optical shutter has an obvious cut-out effect on the laser temporal and spatial profiles. Two-dimensional particle-in-cell simulations show that the high intensity part of a Gaussian laser pulse can be well extracted from the whole pulse. The transmitted pulse with longitudinal steep rise front and transverse super-Gaussian profile is thus obtained which would be beneficial for the radiation pressure acceleration regime. The Rayleigh-Taylor-like instability is observed in the simulations, which destroys the foil and results in the cut-out effect of the pulse in the rise front of a circularly polarized laser.

This paper mainly reported the antiatherogenic mechanism of action of Xueguantong on molecular level. After being established by feeding with high fat diet for 12 weeks, the quail atherosis models were given Xueguantong for 30 days. Then, determining their plasma endothelin and calcitonin gene-related peptide (CGRP) with radioimmunoassay (RIA) and observing the effects of Xueguantong on plasma endothelin and CGRP in quail atherosis models. Results showed that the plasma endothelin increased and CGRP decreased during quail atherosis formation. The plasma endothelin was decreased (P0.05) and CGRP was increased (P0.05) by using Xueguantong. It suggested that one of antiatherogenic mechanisms of Xueguantong was decreasing the endothelin and increasing the CGRP.

A relatively simple interfering-pulses-assisted laser wakefield acceleration (IPA-LWFA) scheme is proposed for enhancing the charge of the LWFA electron bunch. Prior to the short intense pump pulse, two long low-intensity auxiliary laser pulses first interact in the plasma and excite a slow electron plasma wave at the beat frequency. The weak but finite-amplitude plasma wave energizes the affected electrons and acts like a slow-moving grating. Particle-in-cell simulations show that electron trapping in the wakefield of the pump laser pulse, which arrives at a later time, can be significantly enhanced. The charge of the IPA-LWFA electron bunch depends mainly on the intensity of the auxiliary pulses and the time delay of the pump laser.

Arachidonic acid can induce platelet aggregation in rabbits in vitro. The experimental model was designed to observe inhibitory effect of 8 classical recipes of activating blood circulation to remove the stasis on platelet aggregation in vitro. The results showed that each one of 8 classical recipes has inhibitory effect on platelet aggregation in vitro in various degree. Among them, Gexia Zhuyu Tang (GZT), Shentong Zhuyu Tang (SZT) and Shaofu Zhuyu Tang (SFZT) were more effective. The results suggested that inhibitory effect of platelet aggregation produced by 8 classical recipes might be one of mechanisms of blood stasis treatment.